Senators vote on actual bills, not poll questions. Yesterday, they never had a chance to vote on a pure bill about background checks.

The base bill on the Senate floor used model language from Mayor Michael Bloomberg of New York. Besides gun sales, it also applied to temporary and innocent transfers — like letting your spouse borrow your gun for a few hours to take it to the target range. The expansive language would have felonized almost every American gun owner — and that’s not a concept that has 90 percent support.

Although a gun control measure may garner wide approval, a very large fraction of the public that favors the measure does not expect it to reduce crime.

The Manchin-Toomey substitute avoided the temporary transfer problem. But it was hastily drafted in secret, and seriously miswritten. For example, the language, which claimed to outlaw federal gun registration, would actually have legalized one form of registration that is currently banned: building a registry from the sales records that firearms dealers are required to send to the government when they retire from business.

Although President Obama is personally popular, his emotional bullying about Newtown had little effect, since everyone could see that neither the Schumer legislation nor the Manchin-Toomey bill would have made any difference there; the killer’s mother acquired her guns in a state that already had very strict gun laws, and she recklessly left them available to her son, despite his obvious mental illness. Background checks were irrelevant.

For decades, pollsters have observed that although a given gun control measure may garner wide approval, a very large fraction of the public that favors the measure does not expect it to reduce crime. They approve the control with an apathetic “Why not?” Support for gun control is often broad but shallow.

President Obama’s post-election embrace of gun control and of Mayor Bloomberg drove National Rifle Association membership from four million to five million in a few months. The N.R.A. is not the most powerful lobby on Capitol Hill because Wayne LaPierre is the most charming man in town. The N.R.A. wins Congressional votes because it represents millions of Americans who have repeatedly shown that they heed the words of the late Charlton Heston, to “vote freedom first.”